Many devices have been developed in the field of mobility assistance to help people with reduced mobility or provide relief for those who are temporarily disabled and in the rehabilitation phase, or indeed to assist hikers on difficult terrain.
The simplest and best known devices include ambulation devices such as plain walking sticks, crutches, elbow-support crutches, mountaineering sticks and wheeled walkers. These devices comprise a manual gripping member and an elongated section, the end of which is designed to bear on the ground; they can be used singly, or in pairs in some cases. Document FR2845894 describes for example, a device characterized by the fact that it comprises a means of elastic energy restitution designed to propel the elongated section (of a walking stick, for example) forwards upon lifting the lower end off the ground, releasing the elastic energy accumulated through hand pressure on the manual gripping member.
These devices are simple and readily obtainable, but do not assist movement of the lower limbs.
Assisted movement of the lower limbs is particularly developed in “exoskeleton” devices. Thus, document EP1637113 mentions a walking aid device equipped on the one hand with a system for generating hip joint rotational power serving to impart an auxiliary force to the movement of a lower limb and on the other hand, with a system for generating knee joint rotational power. Both systems are interconnected. The device comprising these systems in addition to means for fastening to the human body are carried around the user's waist and on the sides of his/her lower limbs.
Document EP2554150 mentions another type of device, integral with the user's lower limb, comprising hip, leg and foot units in addition to joint units, interconnected and situated on the front and outer side of the lower limb.
Document US20090014042 describes another type of device, intended to reduce the burden on the user's legs. This device is held on the user's crotch and legs, with the mechanical and linking systems being situated between both lower limbs.
These devices have the disadvantage of being difficult and cumbersome to use, as they are not easy to put on, wear and remove.
Other simpler devices are provided on the user's shoe. Document FR2972906 describes a shoe comprising an upper and a sole, wherein this sole comprises two main sections articulated together. These two sections are articulated along a first horizontal transverse axis located substantially under the natural joint between the forefoot and the posterior part of the foot. A system consisting of spring-loaded lever arms, hinge pins and an elastic module (forming a shock absorber) gives the shoe the characteristic of: (1) transforming the kinetic energy into potential energy when the shoe hits the ground by placing the elastic module under pressure (2) keeping the module under pressure during the phase in which the foot is resting on the ground, (3) releasing the elastic module during the propulsion phase (when the foot is raised to take another step).
Documents U.S. Pat. Nos. 6,684,531 and 5,282,325 describe different types of sprung shoes. The soles are equipped with spring-loaded systems, assisting in particular the user's raising the heel during the act of walking, thereby reducing the muscle energy to be produced by the calf.
These shoes provide support for the lower limbs during the act of walking or running. The main disadvantage is that the energy released remains low, as it is more or less proportional to the energy derived from the impact of the shoe on the ground, while remaining lower or at most equal to this energy.
Document EP2699323 concerns a system for assisting the movements of a user's foot, adapted to a support a sliding board or a snowshoe. It comprises a shoe section, the front end of which is mounted such as to pivot in relation to the support and a spring securable to the support so as to rest on a bearing area of the upper, applying pressure to said bearing area when it is brought close to the support. In this case also, the energy released is a function of the energy resulting from the user's movement in addition to the stiffness of the spring. Less spring stiffness appears preferable for the user's comfort, but will provide less assistance with effort.
An aim of this disclosure is in particular to provide a device that is simple to use and put on, allowing the user to adapt the desired level of assistance to the lower limbs by an external energy input, i.e., not derived from the energy resulting from the movement of the lower limbs; the external energy input is adjustable by the user.